For a while, it appeared certain the United States would have no choice but to intervene militarily in Iraq on a scale President Barack Obama — and the American people — clearly would prefer to avoid.

Then it was learned that thousands of Yazidis, members of a minority religious sect fleeing brutal persecution by the Islamist extremists rampaging through Iraq, had been safely removed from their haven on Mount Sinjar.

American air attacks, combined with advances by Kurdish ground troops, repelled the extremists, allowing the Yazidis to escape.

That made the rescue effort much less likely, Defense Secretary Chuck Hagel observed.

That should please those who had hoped our nation’s involvement in Iraq had ended, but Iraq remains vulnerable and may yet require our nation’s involvement on a larger scale.

Politically, Iraq remains a rudderless ship in danger of disintegration, a situation that would adversely affect the entire region. This isn’t how it was supposed to be after the United States and our allies pulled out, believing the Iraqi people were prepared to govern themselves.

So there may be a good argument for greater involvement by America and its allies. France, Britain and Germany have already decided to participate in the fight against the extremists (although not, so far, with troops).

France, which had opposed the 2003 invasion of Iraq, said this week it was sending weapons to the Kurdish fighters who are the main force opposing the Islamists.

Iraq’s own troops, trained and equipped by the United States, have too often fled in the face of the enemy’s advances, abandoning their vehicles and their weapons to the Islamists.

Obama’s final decision may very well be influenced by the behavior of these extremists who are tearing Iraq apart and treating their foes with relentless cruelty.

Despite Hagel’s assessment of the situation, the United Nations on Wednesday said it still regarded Iraq in general to be suffering the highest level of humanitarian crisis. The aggressors show no signs of mercy or moderation.

Let’s face it: These people must be stopped. Even Saudi Arabia, a Sunni stronghold, has decided to contribute millions of dollars to the United Nations to help the fight against terrorism even though the extremists wreaking havoc in Iraq are themselves Sunnis.

Those who stand in their way and don’t share their extremist religious beliefs are being executed. Women are reportedly being kidnapped and sold as slaves.

Ideally, the government in Baghdad should be prepared to defend Iraq on its own, but the political situation there has been so unstable that no effective response can be expected at this time.

Thursday, Prime Minister Nouri al-Maliki reluctantly agreed to step aside now that Iraq’s presidenthas named his replacement, Haider al-Abadi. By giving up the office he won in April’s elections, al-Maliki will please Washington and his many other critics who accused him of looking after his own political allies and therefore failing to unite the country.

Meanwhile, David Ignatius, a columnist for The Washington Post and a longtime observer of the situation in the Middle East, suggested that Obama consider sending retired Gen. David Petraeus and former Ambassador Ryan Crocker to Baghdad as his special envoys.

That, Ignatius wrote, would send a signal that the president is serious about helping the new Iraqi government. And there’s abundant evidence that such help is badly needed in Baghdad.

Had the al-Maliki government been more interested in serving all of the country’s people and less determined to favor its own partisan supporters, the present crisis might have been avoided altogether.